Both primary and metastatic liver cancer is common in the US, and worldwide. The standard treatment for liver cancer is liver resection, where part of the liver containing the tumor is surgically removed. This operation is associated with considerable blood loss, typically between 0.6 - 1 L. Blood loss is adversely associated with patient morbidity and survival, particularly when blood transfusions are required. We have developed a liver resection device that allows coagulation of a plane of liver tissue within 3 min, including major vessels. The device consists of a linear array of electrodes, to which radiofrequency (RF) energy is applied in bipolar fashion between neighboring electrodes. This liver resection device has the potential of reducing blood loss during liver resection surgery to a minimum, with likely increase in patient survival and lowered complication rates. If resection is not possible, tumors are often directly treated by heat- based thermal ablation. Based on the same blade electrode platform, we have in addition developed a prototype circumferential electrode array that allows rapid direct treatment of large tumors, with sufficient advantages in terms of efficacy compared to current available devices. Both types of the electrode arrays are driven by a multi-channel radiofrequency generator (RFG). The output of this RFG is modulated based on measurements of the tissue impedance, which allows us to account for differences in tissue thickness and determine when the tissue has been sufficiently coagulated/ablated. In this project we will produce a clinical prototype RFG and circumferential electrode array suitable for human use, and perform preclinical animal studies. Based on early prototype studies, it is expected that these new devices will lower health care costs and reduce morbidity and mortality.